Condenser



Dec. 9, 1924.

J. M. CAGE CONDENSER 2 Sheets-Sheet 2 Filed Sept. 26, 1921 Patented Dec. .9, 1924.

UNITED STATES 1,518,888 PATENT OFFICE.

JOI-IN M. CAGE, OIE SANTA MONICA, CALIFORNIA.

CONDENSER.

Application filed September 26, 1921. Serial No. 503,342'.

To all whom 4it may conccm; 1

Be it known that I, JoriN M. CAGE, a citizen of the United States, residing at Santa Monica. in the county of Los Angeles and State of California, have invented new and useful Improvements in Condenscrs. ot' which the following is a specification.

This ,invention relates to ignition systems for internal combustion engines, such as automobile and aviation engines, or all types of internal'combustion engines that use a high tension system of ignition. It will be readily understood that, although'I describe my invention particularly as adapted to automobile engines, the ,inven tion is not in the least limited to engines that are used for such purposes.

There are. many objects of this invention, and the objects and the corresponding accomplishments will be best understood from the following detailed description: of typical forms of my system and typical forms of my condenser, but it may be Well to state some of the. general objects and features of the invention before proceeding to such detailed description.

I have found by trial and experimentation that the energy of the present ignition system is not eiiciently concentrated at the spark gap; apparently only a fraction of the energy of the System being delivered at the spark gap `in the form of a spark for igniting the combustible gases. My invention includes, and. revolves about, my discovery of the fact that by placing a suitable condenser, of suitable capacity, in parallel with the spark gap, I am able to very greatly .increase the energy of the resultant spark without increasing the amount of energy necessary to operate the system, and thus Without increasing the pull of energy on the battery. During the time that the secondary circuit of the ignition system is in operation, this condenser is charged, and then immediately discharges, in a series of oscillations, across the spark gap.; deliver'- ing to the spark gap the energy which it has temporarily st-ored, in addition to the energy which, by the normal operation of the system, would reach the spark gap.

I have found that, in' order to obtain eli'ective results with my system, itis necessary that the condenser be properly proportioned, in point ot capacity, to the capacity particularly true where the system also con of the remainder ot the system. This is tains a primary condenser, and Where the induced current 1n the secondary circuit 1s caused by oscillations in the primary circuit4 the other.

I will give further details first regarding the system and its operatlon and regardmg the `speciiic preferred form of conception ot condenser in the following detailedspecification, reference for this purpose being had to the accompanying drawings, in whichz- Fig. 1 is'an exterior view of one form of condenser used by me in a typical ignition system; Fig. 2 is a longitudinal central section of the same; Fig. 3 is a cross section of the same; Fig. 4 isa diagram of a typical ignition system illustrating thel place ot' my condenser in that ignition system; Fig. 5 is an exterior view-of another form of condenser adapted particularly for'application to the ignition systems of Ford cars; Fig. (l is a longitudinal central section of the same;

Fig. 7 is a transverse section of the same;

and llig. 8 is a diagram illustrating the ignition system of aFord car and illustrating the placement of my condenser in that system.

Ishall refer first to the form of device shown in Figs. l to 4, which is the form of device applicable to meet present day automobile ignition systems. In' applying my condenser to an ignition system of. the character here illustrated, it is only necessary to secure the condenser in some suitable manner to any supporting part of the automobile and connect the otherone of its Wires to the single high tension wire that leads roln the high tension coil to the center of the high tension distributor. The condenser having been properly designed for the system, and having been properly connected in the manner above described, the Whole system is then ready for operation. In Fig. 4 I indicate at E an engine cylinder block with its several spark* plugs S connected by wires and then connect one of its wires toa ground to 'the contacts 11 of the distributor head 12, the central Contact 13 of which is connected by high tension wire 14 to one end of the secondary coil, 15. The other side of the secondary coil 15 is connected to wire 18. The primary winding 17 of the coil is connected by wire 18 to one side of the battery B which is-connected at 19 to ground at the other side; the other side of primary winding 17 being connected by wire 20 to the primary breaker 21 whose other side is connected at 22 also to ground. The primary condenser 23 is connected by Wires 24 and 25 around the breaker 21. The action of this simple formy ot ignition system is well known. Upon breaking of the current at the breaker 21, not only is the current induced into secondary coil 15, but also by inductive action, the condenser 23 is charged. As soon as the condenser is charged, it iininediately discharges around through the primary 17 and the oscillatory naturel of the discharge causes a high tension induced current to flow in secondary 15 and through thesecon'dary circuit to the spark plugs.

My condenser V is connected by one wire 30 to the main high tension wire 14 and by another wire 31 to a ground connection; being, in essence, connected into the high tension circuit around the spark gaps. In so connecting my condenser into this circuit it will be seen that Iimmediately add capacity to the circuit; and the capacity which I add is gauged to'be such as to cause the sum total capacity of the secondary circuit, and its inductiveness, to in suchl proportions and bear such relations to each other as causes the period of oscillation in the high tension secondary to be substantially in step with the period of oscillation in the low tension primary. In other Words, when oscillations are passing through the primary circuit, and are inducing'corresponding currents in the secondary circuits, then, 'in my system, the oscillatory frequency of the secondary circuit is such' that the oscillations set up in the secondary circuits tend to amplify and augment the oscillations in the primary, and thus to increase the efliciency of the system as a whole rather than tend to damp 'off the oscillations in the primary.

I provide a condenser of the proper capacity in a very simple and comparativel inexpensive form; made up so as to be sma l in compass in comparison with its electrostaticcapacity; and in such form and construction as 1s not apt to' be deteriorated, disarranged, or broken by any of the influences to which :it may be subjected in an automobile.

In providing a condenser to accomplish `automotive ignition system.

each half having a semi-cylindrical groove in it, so that when the halves are laid together they form a. case With'a cylindrical openin This cylindrical opening is closed by en caps 41. The drawings show the device in full size as used on the average A. cylindrical glass tube 42 is centrally located in the cylinrical-interior of the case, being bonded in and supported by a filling of petrolastic cement (a comparatively line grade of tar which is made especially for use in connection with storage batteries) indicated at 43. This filling has a melting temperature high enough that it will not melt and run, or soften sufficiently to allow the glass tube or other parts to become displaced at the highest temperature reached in the atmosphere around the engine of an automobile. For instance, the melting temperature of the tar which I now preferably use is about 17 5 Fahrenheit.

Inside the glass tube there is a cylindri- ,cally bent sheet of metal, as illustrated at 44, and outside the glass tube there is a similar bent sheet of metal, as illustrated at 45. These sheets are preferably not seamless tubes, but are made by lrolling up steel shim stock about .002 of an inch thick; the' outer sheet being rolled tightly enough that it will grip the outside of the glass tube and the inner one being rolled openly enough that it will expandlagainst the inside of the glass tube. Around the outside condenser plate thus formed a wire 46 is wound two or three times 4and then twisted to hold it tightly in place, and the grounding Wire 47 of the condenser is connected to this wire 46. Inside the glass tube there is placed a hair-pin 48 made of steel piano wire of aboiit the shape illustrated in Fig. 2 and with ends that are substantially parallel, and the hair-pin7 having Sullicient outward resiliency so that the ends press outwardly against the central portions ofthe inner plate 45 to-pre'ss it out against the inner face of the time 42. The inner end of the high tension wire 48 is connected at 49l to the upper part ot-the hair-pin. The hair-pin thus performs the oiiice of pressing the inner plate out against the glass tube and also of makig electrical connection to the inner plate. igh tension wire 48 extends out through the saine end cap 41 as does the ground wire 47. It will be noted that the two plates 44 and 45 are of lesser length than the glass tube, sufficient excess length of the glass tube being thus provided to prevent leakage around the end. The glass tube is preferably of the quality known asl yrex glass. This quality ofglass has a igh dielectric co-efiicient and is substantially immune from breakage or fracture due to an reasonable changes of temperature. I fin it very satisfactory for use in my condenser. In the size of condenser' herein described, the plates are each approximately seven square inches area. Of

course, any suitable material may be used thicknesses and rolls very evenly.

Alter experimenting with a large. number ot dielectrics for separating the plates and for filling the space'between them and the case and for covering the exposed portions ot the glass and plates to prevent brushing I have found this combination of glass and petrolastic cement to be mosthighly ciicient. The tar cement has a suili-v ciently high dielectric co-etticient, possesses a sufficient rigidity to hold the parts in place, and at the same timel has the very desirablequality of preventing brushing because it has an adhesive quality both to the metal and to the glass that prevents its beingraised :trom the metal and glass by the electric action. Paraline, for instance, I find is comparatively easily raised from the glass by the electric action, forming a thin open space in which brushing takes place. This is not trueof the adhesive tar. Furthermore, the tar has all the advantage of a solid although it can be poured into the container while in liquid form, and has none of the disadvantages of a liquid. I have found in using a liquid dielectric that iton any occasion an arc or local heating takes place, a gas bubble or bubbles will be formed which immediately causes current leakage. This does not take place in the tar.

Iny assembling this condenser the two sides of the bo-x are glued together and one end glued and nailed on. Then the entire assembly of glass tube, the two plates, and the wire connections, ctc. having been previously put together, is inserted in the container with the wires 47 and 48 projectin Tar is then poured in at a tempera-ture hig .enough to keep it liquid, care being taken that the tar does not boil, in order to avoid any bubbles being formed in the finally solidified tar. Usually two or three separate pourings of the tar are necessar in order to fill the container completely to thel top. The cap is then put in place preterably being glued and nailed. The finished box may be pro-vided with any suitable mount-ing means. pFor instance, I may provide a' pair of bolts 50 that project through the two halves of the box, these bolts thus providing means for holding the box together and also forA mounting them on 'a suitable part of the automobile.

In Figs. 5 to 8,Ihave shown a similar form of4 condenser whichy embodiesA four units in onecasing, and particularly adapted to such ignition systems as are used on the Ford automobile. I'Iere I show a metal container with a cap 61 that is put into place as the parts are asseinbled. This container being most conveniently suspended on the radiator stay rod, I provide the container 60 with a pair of wire clips 62l that may be easily bent around the stay rod to support thecontainer. Container 60 is in this casepret'erably cylindrical and it contains four sets of condenser elements 63, each like the condenser element hereinbefore described, in that it is made up of a' glass tube 64, outer and inner plates and 66, anda high tension wire connection 67 connected to the inneryplate in the manner hereinbefore described. There arc four such high tension wire connections, cach leading out through the end cap 68. For this purpose the end cap is perforated as shown at 69, and a rubber or fibre or other suitable perforated washer 70 is placed inside thev end cap as illustrated; the washer 70 being made of insulating material, and the perforations. 69 in the end cap- 68 being suiiciently large to space their edges from their various Wires. There is only a single lll) ground wirey 71, and this single ground wire leads up between the four container elements and is connected to the wire 4:6 l

that is wound around all four' of the condenser elements and is thus wound around in contact with all four of theA outer plates 65. How this is accomplished can be clearly seen from the drawings. Thus we have a condenser, made up similarly to that herein.v

before described, but having four independent high tension outlets and one common ground wire. The interior of this condenser is filled with the same tar material as hereinbefore described. Forr the ignition system of Fords the capacity and dimensions of each condenser element is approximately the salice as for the standard apparatus hereinbefore described. In each case the plates have an area of an average of about seven vsquare inches (this can be varied somewhat andv still get good4 results); the glass is of the quality known as pyrex and has a thick.

ness of about 1.5 millimeters. The drawin s show both types of condenser substantia y in full size.

The system ot`l connections of this condenser into the Ford ignition system is shown in Fig. 8. Here the battery is indicated at B one side of which is grounded as at 80, and the other side of which is connected by wire 81 and 82 to one side of the primary windings 83 of the four induction coils. The other side of each primary winding 83 is connected through the coil vibrator and by individual wire 84; to an individual contact 85 on the timer T, the central contact of which is connected as shown at 86 to ground. The secondary winding 87 of each induction coil is connected by individualwire 88 llU to the spark plugs S of the engine E. The primary circuit condensers 23 are connected by wires 9() to one side of the primary windings andby wires 91 and 92 to ground. The ground wire 71 of my condenser V is connected to ground as indicated, while the Ifour high tension Wires 67 are connected individually to the four wires 88 that lead to the spark plugs. Without the necessity of followin out the circuitings here itwill be seen that t e condenser V occupies the same position with relation to the spark gaps that it occupies in the form shown in F ig'. 4; the only difference here being that there is one condenser unit for each spark plug Whereas in Fig. 4 there is one condenser' unit for all the spark plugs.

Having described a preferred form of my invention, I claim:

l. A condenser embodying a container, a dielectric tubeV therein, a resilient conductor plate inside the tube springing out against it, a resilient conductor plate outside the tube resiliently clasping it, and a filling for the container of dielectric material which is adhesive to the tube andplates and solid at ordinary 'temperatures to support them in the container.

, 2. A condenser embodying a container, a dielectric tube therein, afresi'lient conductor plate inside the tube springing out against it, a resilient conductor plate outside the tube resiliently clasping it,.a resilient hair pin inside the tube pressing out against the inner plate, a conductor connected to the hair pin, a Wire wound around the outer plate,

a conductor connected to the wire, and a fillin of dielectric material for the container so 1d at ordinary temperatures to support the tube and plates in the container.

3. ,A condenser embodyin a container, a dielectric tube therein, a resilient conductor plate inside the tube springing outagainst it, aresilient conductor plate outside the rand tube.

4. A condenser embodying a container, a dielectric tube therein, a resilient conductor plate inside the tube springing out against the inner surface `of the tube, a resilient con' ductor plate outside the tube 'and resiliently springin in against the outer surface of the tube, an a dielectric filling for that container inside and outside the tube.

In Witness that I claim the foregoing I have hereunto subscribed my name this 8th day of September, 1921. c JOHN M. CAGE. 

